Ways to fix chainline (GT Team Avalanche)

[kicks66]

I'm building up a 1990s GT Avalanche. I've installed a MT510 hollowtech BB and then a MT510 12 speed chainset. However, now I've also installed the rear casette, I'm not getting a great chainline between the two - with the front chainring being basically in line with the last cog on the casette.

I've moved the BB washers so I have 1 on the drive side and 2 on the non-drive side, other than that what else can I do? Is it something related to the BB/chainset? Are there narrower BBs / chainrings I could get instead?

 

[hamster]

Is this a Boost chainset for a wider back end?

 

[Imlach]

A bit of a bodge is to get extra long chainring bolts and spacers and offset it

 

[kicks66]

Is this a Boost chainset for a wider back end?

I don't believe so: https://bike.shimano.com/en-EU/product/component/deore-m6100/FC-MT510-1.html

 

[hamster]

The smoking gun is that it will handle 142/148mm back ends. Check the installation manual, it will be something to do with spacers.

 

[Takingabreak]

That's hurting my eyes. It's like trying to play a dvd on a betamax player

 

[Imlach]

Can you not remove the spacer and drive the cup in further? Not that it'd give you loads I suppose

Or go square taper!

 

[nstarmore]

52mm is boost chainline. That's a bit naughty of Shimano listing that as compatable with 135 axle spacing in all honesty.

3mm chainring spacers are the way forward with that one

 

[kicks66]

52mm is boost chainline. That's a bit naughty of Shimano listing that as compatable with 135 axle spacing in all honesty.

3mm chainring spacers are the way forward with that one

So would it be best to find a chainset with a narrower chainline? It seems all their single ring deore options have the same chainline:

SHIMANO DEORE 2-PIECE CRANKSET for 135 mm, 142 mm and 148 mm O.L.D. Frames 1x11/10-speed | SHIMANO BIKE-EU

The SHIMANO DEORE FC-M5100-1 mountain bike crank delivers precise and reliable shifting for 1x10 or 1x11-speed drivetrains.

bike.shimano.com

Are there suggestions for other ones to use for a 135 rear spacing?

 

[nstarmore]

I've just done some Googling as this has perplexed me somewhat and came across this thread on pink bike.

Note at the end "I believe Shimano redesigned tooth profile on the new groupset's chainrings somehow to work well with a 52mm chainline on non Boost frames."

No idea how much truth there is in this but could be the case, Shimano must have a reason for listing it as compatible with 135mm where their other 52mm chainline cranks don't.

Have you actually tried it yet? I would say, if it works then run with it. Personally I would still put chainring spacers in though.